Orientador: Wesley Rodrigues Silva / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-17T09:09:30Z (GMT). No. of bitstreams: 1 Guerra_TadeuJosedeAbreu_D.pdf: 2780455 bytes, checksum: a4bd5aa0f423ec7226c91f0cff7655f9 (MD5) Previous issue date: 2010 / Resumo: Neste trabalho investiguei aspectos da história natural da erva-de-passarinho lenhosa Psittacanthus robustus Mart. (Loranthaceae) em áreas de campos rupestres da Serra do Cipó, sudeste brasileiro. Essa espécie foi observada parasitando de oito espécies de hospedeiras pertencentes a cinco famílias, embora espécies arbóreas da família Vochysiaceae sejam as principais hospedeiras. O padrão de distribuição espacial é agregado nas hospedeiras e também na escala da paisagem. A prevalência aumentou em função do tamanho para as quatro espécies de hospedeiras avaliadas. A propagação se dá exclusivamente por dispersão de sementes e o período de frutificação se estendeu de maio a setembro (estação seca). Seus frutos são ornitocóricos e o principal dispersor foi a guaracava-de-topete-uniforme, Elaenia cristata (Tyrannidae), que descarta as sementes por regurgitação e depositando-as durante ato de limpar o bico nos poleiros. Esse pássaro se empoleira preferencialmente nas hospedeiras infectadas e a remoção experimental de P. robustus reduziu significativamente a deposição de sementes nas quatro espécies de hospedeiras. Esses resultados indicam que a distribuição agregada nas hospedeiras está relacionada ao comportamento do dispersor que promove uma deposição desproporcional de sementes sobre hospedeiras infectadas. Além disso, a abundância de E. cristata aumentou com disponibilidade de plantas em frutificação nos afloramentos rochosos, promovendo retro-alimentação positiva na dispersão e deposição de sementes. Esse parece ser o principal processo que levam a distribuição agregada dessa erva-de-passarinho na escala da paisagem. Hospedeiras mais altas têm maiores chances de receber sementes, indicando que a maior prevalência em hospedeiras mais altas está relacionada com seleção de poleiros pelos dispersores. Psittacanthus robustus floresceu entre novembro e março (estação chuvosa). As flores apresentam características tipicamente ornitófilas, incluindo antese diurna, corola amarela e produção copiosa de néctar diluído, que é reabsorvido caso não seja consumido pelos polinizadores. Observei oito espécies de beija-flores e duas espécies de pássaros como visitantes florais, mas os beija-flores Eupetomena macroura e Colibri serrirostris (Trochilidae) foram os principais polinizadores. Não encontrei diferenças significativas na produção de sementes entre flores polinizadas com o próprio pólen ou de forma cruzada. No entanto, esses tratamentos produziram mais sementes do que flores controle expostas aos polinizadores indicando que reprodução é limitada pela deposição de pólen. Essa planta não produziu sementes por apomixia e apresentou capacidade limitada de produzir sementes de forma autônoma por autopolinização, evidenciando a importância da polinização por beija-flores na reprodução. Por fim, apresento dados sobre a história natural do percevejo Eurystethus microlobatus (Pentatomidae), uma espécie fitófaga associada à P. robustus. Esse percevejo apresenta comportamento gregário e cuidado maternal. Os indivíduos se abrigam mais freqüentemente nas raízes e ramos onde se encontram melhor camuflados na casca de P. robustus. Além disso, esse percevejo produz exudato açucarado que é utilizado como recurso alimentar por formigas, que os protegem contra inimigos naturais ao de todo o dia. A complexa gama de interações envolvendo plantas hospedeiras, aves frugívoras e nectarívoras, além de insetos herbívoros sugerem que P. robustus desempenha importante papel na manutenção da biodiversidade nos campos rupestres da Serra do Cipó. / Abstract: In this study I investigated some aspects of the natural history of the woody mistletoe Psittacanthus robustus Mart. (Loranthaceae) in rocky outcrops in the Serra do Cipó, southeastern Brazil. This species was recorded parasitizing eight host species in Five families, although trees within Vochysiaceae comprise the main hosts. Pattern of distribution was clumped within host trees but also at landscape scale. Prevalence increased with height for the four hosts species evaluated. Dissemination occurs exclusively through seed dispersal and the fruiting period extends from April to September (dry season). The fruits are ornithochorous and the main seed disperser was the plain-crested Elaenia, Elaenia cristata (Tyrannidae), which regurgitated and deposited seeds on perch during bill wiping. This bird perched preferentially on already infected hosts and experimental removal of mistletoes decreased significantly seed deposition on four host species. These results indicate that aggregated distribution on host trees is related to behavior of seed dispersers, which promoted non-random seed deposition on already parasitized trees. In addition, abundance of E. cristata increased with availability of fruiting mistletoes on rocky outcrops, promoting a positive feedback in seed dispersal and deposition. This seems to be the main processes leading to a highly clumped distribution of woody mistletoe at landscape scale. Taller hosts have higher chances to receive seeds, what indicates that increased prevalence on taller trees is related to perch selection by seed dispersers. Psittacanthus robustus bloomed from November to March (rainy season). Flowers presented characteristics typical from ornithophilous plants, including diurnal anthesis, yellow corolla, and secretion of abundant diluted nectar, which is reabsorbed if not utilized by pollinators. I observed eight hummingbird species and two passerine species as flower visitors, but the hummingbirds Eupetomena macroura and Colibri serrirostris (Trochilidae) were the main pollinators. I found no differences in seed set between flowers hand pollinated with own pollen or with pollen from distinct genet. However, these treatments set significantly more seeds than flowers exposed to pollinators, indicating that reproduction is pollen limited. This plant did not produce seed through apomixis and presented a limited capacity to produce seeds through autonomous self-pollination, highlighting the role of hummingbirds on plant reproduction. Finally, I reported data on natural history of the stinkbug Eurystethus microlobatus (Pentatomidae), a phytophagous species associated to P. robustus. This stinkbug presents a gregarious behavior and maternal care. Individuals are likely to rest on roots and shoots where they camouflage within host bark of P. robustus. Moreover, this stinkbug produces honeydew that is utilized as food source by ants, which protect them against their natural enemies throughout the day. The intricate interactions involving hosts plants, frugivorous and nectarivorous birds and insect herbivores suggest that woody mistletoes have an important role in sustaining the biodiversity in rupestrian fields in the Serra do Cipó. / Doutorado / Ecologia / Doutor em Ecologia

Orientadores: Wesley Rodrigues Silva, Paulo Roberto Guimarães Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-13T12:23:21Z (GMT). No. of bitstreams: 1 Amatuzzi_MariaClaraOleski_M.pdf: 1407858 bytes, checksum: bb5c3ae5328b68092befea78e47ba7d7 (MD5) Previous issue date: 2009 / Resumo: O mutualismo planta-frugívoro é bem conhecido como importante processo na manutenção dos ecossistemas. O frugívoro obtém o recurso alimentar da polpa e dispersa as sementes da planta. A crescente perda e fragmentação de ambientes naturais devem afetar essas interações. Portanto, conhecer quais são os efeitos desta degradação na dispersão de sementes é um passo importante na tentativa de preservação dos ecossistemas. A abordagem de redes vem sendo usada atualmente a fim de entender melhor a estrutura, funcionamento e evolução de diversos tipos de interações. Explorei alguns padrões de extinção de espécies em uma rede de interações mutualísticas frugívoro-planta do Parque Estadual de Intervales (PEI) simulando extinções de frugívoros e plantas e observando os efeitos na sua estrutura. A rede frugívoro-planta do PEI é uma rede típica de interações mutualísticas com estrutura extremamente aninhada; baixa conectância; baixos graus médios tanto de plantas como dos animais; prevalência de interações fracas e ocorrência de interações assimétricas. As co-extinções ocorreram muito lentamente com as remoções de especialistas e geram um declínio considerável na riqueza de espécies do outro grupo, somente após remoção de 80% das espécies. Remoções aleatórias de espécies geraram um padrão quase linear de co-extinções, após a remoção de 50% das espécies observa-se um maior impacto na riqueza da rede. A remoção das espécies ameaçadas de extinção causou impacto semelhante ao observado com as remoções aleatórias. Em geral, ocorre um padrão de surgimento de pequenos componentes, a partir da remoção de 5% das espécies, porém há sempre um grande e aninhado componente. O aninhamento da rede foi pouco modificado com as simulações. A rede perde o aninhamento mais rapidamente durante a remoção de generalistas. Os resultados reforçam a idéia de robustez dessa rede que é gerada pela suas características estruturais. As espécies mais importantes para a manutenção da estrutura e riqueza de espécies da rede são as generalistas. / Abstract: The frugivore-plant mutualism has been recognized as an important process in maintaining terrestrial ecosystems. Frugivores feed on fruits and disperse their seeds. The increase of habitat fragmentation and loss may affect these interactions. Therefore, understanding the effects of these disturbances on seed dispersal process may help to predict shifts in the remaining ecosystems. In this sense, the network approach has been used to describe the structure and investigate function and evolution of different types of interactions. I explored different patterns of extinction in a network of mutualistic frugivore-plant interactions of the Parque Estadual de Intervales (PEI) by simulating the removal of frugivores and plants and observing the effects on its structure. The PEI network as a typical mutualistic network with highly nested interactions; low connectance; small average number of interactions for both plants and animals; prevalence of weak interactions and occurrence of asymmetric interactions. When removing specialists, coextinctions occurred very slowly, leading a significant decline on species richness only after the removal of 80%. Random removal of species created an almost linear co-extinction pattern, showing important cumulative loss of species after removal of 50% of species. Species diversity declined most rapidly with the removal of the generalists. The removal of endangered species caused patterns of co-extinction similar to those caused by the random removal. In general, PEI network showed a pattern of break down of small clusters after the extinction of just 5% of species, although a large and nested cluster stil observed. The nested structure of the network was slightly changed through the simulations. The network lost its nested structure more rapidly when generalists species were removed. These simulations support the notion that mutualistic networks are robust to extinction and generalists are the most important species for the maintenance of structure and species richness of these networks. / Mestrado / Mestre em Ecologia

Orientador: Ricardo Ribeiro Rodrigues / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-08T15:03:54Z (GMT). No. of bitstreams: 1 Souza_FlavianaMalufde_D.pdf: 1240667 bytes, checksum: 7ce64c73162dd8df01a650e6144d90aa (MD5) Previous issue date: 2007 / Resumo: As interações das árvores do dossel com as plantas que se estabelecem sob suas copas e suas conseqüências na organização da comunidade são pouco conhecidas para as florestas tropicais. Neste trabalho, investigamos como a deciduidade e a síndrome de dispersão das árvores do dossel podem influenciar a estrutura e riqueza da comunidade arbustivo-arbórea do subosque em um remanescente de Floresta Estacional Semidecidual, localizado na Estação Ecológica dos Caetetus, Gália - SP. Em uma parcela permanente 10,24 há amostramos todas as árvores do dossel (dossel e emergentes) e os indivíduos com diâmetro à altura do peito '> ou =' 4,8com situados sob suas copas. As espécies decíduas apresentaram maior abundância relativa e maior proporção de espécies secundárias iniciais sob suas copas do que as espécies perenifólias. Dentre os grupos de dispersão das árvores do dossel, as espécies autocóricas apresentaram maior abundância relativa de indivíduos coespecificos sob suas copas, enquanto as espécies anemocóricas e zoocóricas não diferiram entre si. A abundância relativa de indivíduos zoocóricos embaixo das copas não diferiu entre os grupos de dispersão, mas a riqueza de espécies zoocóricas foi maior sob as espécies zoocóricas do dossel. Esses resultados indicam que a deciduidade pode favorecer a sobrevivência e ao crescimento das espécies mais exigentes em relação à luz como secundárias iniciais, provavelmente em decorrência do aumento na quantidade e na qualidade da luz que chega ao subosque ...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: In tropical Forest, the consequence of interactions between canopy and understory plants to the community organization are poorly understood. We insvestigated how deciduousness and dispersal syndromes of canopy tree species could influence the community structure and species richness in a Seasonal Semideciduous Forest located at Caetetus Ecological Station Reserve, in central-western São Paulo state, Brazil. In a 10,24 ha permanent plot, we sampled all overstory trees (canopy and emergent trees) and the trees with dameter at breaster height '> ou =' 4,8 cm under their crowns (understory trees). Deciduos canopy trees showed higher relative abundance and proportion of early secondary species under their crowns than evergreen trees. Autochorous canopy trees presented higher relative abundance of cosnpecific individuals under their crowns, while there was no difference between wind and animal-dispersed canopy trees. The relative abundance of animal-dispersed trees in the understory did not differ among dispersal guilds, but estimated zoochorous species richness was higher under zoochorus canopy trees. The results suggest that the deciduousness of canopy trees may facilitate the survival and establishment of species with higher requeriments, most possibly by providing an increase in the amount and quality of the light that reaches the understory when canopy trees are leafless ...Note: The complete abstract is available with the full electronic digital thesis or dissertations / Doutorado / Doutor em Biologia Vegetal

Made available in DSpace on 2014-07-29T16:21:21Z (GMT). No. of bitstreams: 1 Dissertacao Analice.pdf: 1264995 bytes, checksum: fd57030ccf06e4f9597e629820353e72 (MD5) Previous issue date: 2009-02-25 / The species are behaving differently to the process of fragmentation and this behavior will depend on the relationship between behavioral, morphological and ecological traits with the physical attributes of the landscape. The body size is a major ecological factors and some links are made between the size and dispersal ability, capacity for perception of the environment and likelihood of occurrence. In this way, the objective was evaluate as is the distribution of mammals in fragmented landscape of Aruanã, Goiás, Brazil testing the following hypotheses: 1) Fragments larger and less isolated have high species richness, 2) species of greater body mass are less affected by fragmentation due to greater dispersal ability; 3) species of greater body mass are distributed more homogeneous in the landscape. We recorded 19 species of mammals, the area but not isolation, was a significant predictor to explain variation in species richness of mammals with larger areas being richer than smaller areas. Large species like jaguar and puma, red brocket deer and gray brocket deer, collared peccary, ocelot and agouti were sensitive to the effect of the area and therefore the effect of fragmentation, which is not confirmed the second hypothesis. However, these species were not restricted only to larger areas, being found also in small fragments used as a temporary source of resources. The puma was the only species that showed significant incidence-isolation relationships. There was no pattern of a homogeneous distribution for these species, but for the tapir, with higher body mass recorded, the results were exactly the opposite of what was observed. The minimum area estimated that 50% or more of the populations of sensitive species occurs in fragmented landscape was 520 hectares. These results reinforce the importance of maintaining forest fragments, almost all belonging to private lands in the conservation of species. / As espécies se comportam de maneiras diferentes ao processo de fragmentação e esse comportamento dependerá da relação entre traços comportamentais, morfológicos e ecológicos com os atributos físicos da paisagem. O tamanho corporal é um dos principais fatores ecológicos e algumas relações são feitas entre tamanho e habilidade de dispersão, capacidade de percepção do ambiente e probabilidade de ocorrência. Nesse sentido, o objetivo do trabalho foi avaliar como ocorre a distribuição de mamíferos na paisagem fragmentada da região de Aruanã, Goiás testando as seguintes hipóteses: 1) Fragmentos maiores e menos isolados possuem maior riqueza de mamíferos; 2) Espécies de maior massa corporal são menos afetadas pela fragmentação por possuírem maior habilidade de dispersão e 3) Espécies de maior massa corporal estão distribuídas de forma mais homogênea na paisagem. Foram registradas 19 espécies de mamíferos e a área, mas não isolamento, foi um preditor significativo para explicar a variação da riqueza de espécies de mamíferos com áreas maiores sendo mais ricas do que áreas menores. Espécies geralmente de maior tamanho corporal como a onça-pintada e parda, veado-mateiro e catingueiro, cateto, jaguatirica e cutia foram sensíveis ao efeito da área e consequentemente ao efeito da fragmentação, o que não corroborou a segunda hipótese. Em termos de isolamento, a onça-pintada, tamanduábandeira, veado-mateiro, tatu-canastra, tamanduá-mirim e gato-maracajá apresentaram relações incidência-isolamento significativas. No entanto, essas espécies não estiveram restritas apenas às maiores áreas, sendo encontradas também em pequenos fragmentos que elas podem utilizar como fonte temporária de recursos. Não foi verificado um padrão de distribuição homogêneo para essas espécies, mas para a anta, com maior massa corporal registrada, os resultados foram exatamente o oposto do que se observou. A área mínima estimada para que 50% ou mais das populações de espécies sensíveis persistam na paisagem fragmentada foi de 520 hectares. Esses resultados reforçam a importância da manutenção de fragmentos florestais, praticamente todos pertencentes a propriedades particulares, na conservação das espécies.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-07-28T19:07:37Z No. of bitstreams: 2 Tese - Rosana Talita Braga - 2016.pdf: 2100004 bytes, checksum: 888ddcc97f7af7b38c2dc63d5383d0d7 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-01T13:19:21Z (GMT) No. of bitstreams: 2 Tese - Rosana Talita Braga - 2016.pdf: 2100004 bytes, checksum: 888ddcc97f7af7b38c2dc63d5383d0d7 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-01T13:19:21Z (GMT). No. of bitstreams: 2 Tese - Rosana Talita Braga - 2016.pdf: 2100004 bytes, checksum: 888ddcc97f7af7b38c2dc63d5383d0d7 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Spatial patterns of population abundance: a review of predictions and theoretical models in ecology and biogeography: The search for mechanisms influencing population demographic patterns has continuously increased. The early models described how closed populations performed, considering only local demographic attributes. However, the spatial configuration and dispersal rates in demographic patterns become determinant factors for understanding patterns of distribution and abundance. As a result, spatially explicit models have been improved to be analytically tractable by using computer simulations. Because species are not infinitely disperse, here I investigated the theoretical predictions to understand what determine range boundaries and distribution patterns, as well as abundance patterns over species ranges. I conclude that empirical studies are crucial to a more accurate understanding of population dynamics along space and time to validate the theoretical predictions made about the geographic distribution of species. / Ao longo da história da ecologia, predições e modelos teóricos sobre mecanismos estruturadores dos padrões demográficos populacionais se intensificaram. Inicialmente, os modelos desenvolvidos ocupavam-se em descrever como populações fechadas se comportavam considerando unicamente atributos demográficos que ocorrem localmente. Posteriormente, tornou-se claro que considerar também a configuração do espaço bem como as taxas de dispersão nos modelos demográficos eram fatores determinantes para compreender padrões de distribuição e abundância. Diante destes avanços, modelos espacialmente explícitos vêm sendo desenvolvidos e aprimorados, sendo eles analiticamente tratáveis ou provenientes de simulações computacionais. Como as espécies não se dispersam infinitamente, elucidei também predições teóricas sobre o que determina o limite de distribuição geográfica (distribuição geográfica) e que padrões de distribuição de abundância são esperados ao longo da distribuição geográfica de uma espécie. Testes empíricos para aprimorar a compreensão da dinâmica populacional (temporal e espacial) é urgentemente necessária para validar as predições teóricas feitas a respeito da distribuição geográfica das espécies.

There is currently worldwide pressure to establish Marine Protected Area (MPA) networks which are self-sustaining and will persistently protect habitats and species. In order for MPA networks to be effective, the species targeted for conservation must be able to disperse between protected areas and maintain a gene-flow necessary for population sustainability and persistence. This warrants new research on how to quantify and map faunal dispersal to ensure that protection will be effective and sustainable. Population genetic methods have merit, with the ability to track parentage and gene flow between areas directly. However the costs, quantity of samples, and time required to genetically quantify dispersal for multiple species make these approaches prohibitive as the only method of assessment, especially in relatively inaccessible offshore waters. Dispersal modelling is now becoming more accessible and may fulfil immediate needs in this field (although ground truthing will be necessary in the future). There have been very few dispersal modelling studies focussed on deep sea or offshore areas, predominantly due to the lack of high resolution hydrodynamic models with sufficient geographic extent away from shore. Current conclusions have been drawn based on shallow water coastal studies, informing offshore MPA network size and spacing. However the differences between these two environments may mean that dispersal abilities are not comparable. Deep water receives less influence from wind and weather, and the scales are vastly different in terms of a) the depth ranges covered, b) the planktonic larval durations (PLDs) of animals, and c) the geographic areas concerned as a consequence. Global hydrodynamic models with reasonable resolution are now becoming more accessible. With the outputs from these models, and freely available particle simulators, it is becoming more practical to undertake offshore deep water dispersal studies. This thesis aims to undertake an analysis of these accessible modelling tools within a deep sea context. The guidelines which are currently available to dispersal modellers are yet to encompass the needs of deep water modellers which may require some additional considerations given the extended depth range covered and the different hydrodynamic drivers away from the air/sea interface. Chapter 1 reviews the larval dispersal process, the factors which may affect dispersal success, and those which should be incorporated into future predictions of dispersal. The current methods for assessing larval dispersal are explored covering genetics, elemental tagging and modelling approaches with an extended look at modelling considerations. Existing marine conservation policy is also touched on in the context of connectivity and larval dispersal. Chapter 2 is designed to inform future deep sea modellers on how to parameterise and understand a dispersal model. As models appear as a ‘black box’ to the majority of users, sensitivity tests can offer a way of scaling model inputs and tempering expectations from model outputs. A commonly used model pairing (the HYCOM hydrodynamic model and the Connectivity Modeling System) is assessed, using parameters which link to the temporal and spatial scales of mixing in the modelled system: timestep of particle tracer, horizontal and vertical positioning of release points, release frequency of larvae, and temporal range of simulation. All parameters were shown to have a decreased sensitivity with depth, with patterns reflecting local watermass structure. Future studies observing similar hydrodynamic conditions seeking to optimise their model set up would be advised to stratify their model release locations with depth. A means to incorporate all sensitivity test results into optimal input parameters for future studies is demonstrated. Chapter 3 investigates whether dispersal models provide any advantage over a “sphere of influence” estimate based on average current speeds and PLDs: there is no use pursuing dispersal modelling if the outputs are too erroneous to provide any advantage over a back-of-the-envelope calculation. This chapter examines the outputs of two dispersal models driven by two different hydrodynamic models in order to observe the variability in prediction between models. This model comparison revealed a greater disparity between hydrodynamic model predictions than has been previously understood by ecologists. The two models compared (POLCOMS and HYCOM) may equally be considered as suitable to promote realism in the study region, but slight differences in resolution and numerical error handling resulted in dispersal predictions from which opposing conclusions can be drawn. This chapter therefore emphasises the necessity for model ground truthing before predictions can be trusted. Chapter 4 assimilates the findings of the previous chapters and applies their advice to a study of MPA network dispersal connectivity. Using the hydrodynamic model which performed best in chapter 3 (HYCOM), a simulation was undertaken for cold water coral (Lophelia pertusa (Linnaeus 1758)) larval dispersal between already established MPAs in the NE Atlantic. As larval characters have only been observed ex situ, dispersal was simulated using two null models (passive and active vertical migration) and averaged to provide an intermediate prediction. A method for assessing dispersal within MPAs and MPA networks is offered based on the intermediate prediction, as well as a network wide assessment of the difference in dispersal patterns for passive and active larvae. It was found that the existing network performs well at supplying larvae to non-networked sites, but performs poorly at supplying other MPAs. The ‘best’ MPAs were central to the network and facilitated the traverse of regional gaps in suitable habitat. The ‘worst’ MPAs were peripheral to the network and small in size. Network-wide passive and active dispersal matrices had no significant difference between them. However site specific variability in the effect of vertical migration was detected subject to variability in local topographic barriers to dispersal, only some of which could be surmounted with vertical migration. All chapters aim to inform future deep sea dispersal modellers, and encourage exploration of this tool in other contexts, as well as marine conservation. The thesis cautions against the transplantation of shallow water assumptions to deep water environments, and advocates region specific studies and mandatory ground truthing of predictions. An upcoming study will ground truth the findings of this thesis with both genetic and oceanographic data, allowing the accuracy of study results to be quantified.

The fishery for octopus in Northwest Mexico has increased to over 2,000 tons annually, but to date the specific composition of the catch has been ignored. With at least three main species targeted by artisanal fisheries in the region with distinct life histories, the lack of basic biological information about the distribution, metapopulation size and structure of each species could impede effective fisheries management to avoid overexploitation. We tested if different life histories of three species of octopus could help predict observed patterns of genetic diversity, population dynamics, structure and connectivity and how this information could be relevant to the sustainable management of the fishery. We sequenced two mitochondrial genes and genotyped seven nuclear microsatellite loci to identify the distribution of each species in 20 locations from the Gulf of California and the west coast of the Baja California peninsula. We tested five hypotheses derived from population genetic theory based on differences in the fecundity and dispersal potential for each species. We discovered that Octopus bimaculoides with low fecundity and direct development (without a planktonic phase) had lower average effective population size and genetic diversity, but higher levels of kinship, population structure, and richness of private alleles, than the other two species. These features indicated limited dispersal and high local recruitment. In contrast, O. bimaculatus and O. hubbsorum with higher fecundity and planktonic phase as paralarvae had higher effective population size and genetic diversity, and overall lower kinship and population structure than O. bimaculoides. These observations supported higher levels of gene flow over a larger geographical scale. O. bimaculatus with the longest planktonic paralarval duration and therefore larger dispersal potential had differences in the calculated parameters possibly associated with increased connectivity. We propose O. bimaculoides is more susceptible to over exploitation of small, isolated populations and could have longer recovery times than the other two species. This species may benefit from distinct fishery management within each local population. O. bimaculatus and O. hubbsorum may benefit from fishery management that takes into account metapopulation structure over larger geographic scales and the directionality and magnitude of larval dispersal driven by ocean currents and population connectivity among individuals of each locality. The distribution of each species and variations in their reproductive phenology is also important to consider when establishing marine reserves or seasonal fishing closures.

Trade-offs prevent selection from driving all fitness-enhancing traits towards values that would maximize fitness. Life-history trade-offs, such as the one between survival and reproduction are well-studied, yet trade-offs can also involve behavioural or cognitive traits. Because males and females have different routes to successful reproduction, the optimal resolution of life-history trade-offs can differ between the sexes. However, shared genome can constrain the evolution of sex-specific adaptations. In this thesis, I explore the links between sex-specific life histories, cognition and behaviour. I start by linking sex differences in life histories to sex differences in learning performance in the outcrossing nematode Caenorhabditis remanei (Paper I). I report that age-related learning differs between the sexes and that it corresponds to sexual dimorphism in life history. Then, I use experimental evolution to select for learning performance to study the patterns of genetic correlations between learning and life-history traits in both sexes (Paper II). The results demonstrate the correlated evolution of sexual dimorphism in life history indicating sex-specific fitness costs and benefits of learning. In Paper III I use the fruit fly Drosophila melanogaster to ask about the extent to which cognitive and demographic aging are independent. The results reveal that selection for late-life reproduction alone bears no effect on late-life learning and that joint selection on late-life learning and reproduction does not yield lifespan benefits. The selection might have affected, however, female age-specific reproductive effort. Motivated by the questions on aging I proceed to ask why a potent lifespan extending drug – rapamycin affects sexes differently (Paper IV). I take a closer look at the trade-off between growth, lifespan and reproduction and propose that the sex experiencing a stronger relationship between size and fitness pays a higher cost of lifespan extension. Finally, I focus on another sex-specific trait – dispersal (Paper V). I conduct experimental evolution to uncover a negative genetic correlation between dispersal and reproduction and show sex-specific genetic variation for dispersal. In summary, my thesis unravels the complex pattern of interdependence between life-history, behavioural and cognitive traits, where sex emerges as an important factor that can maintain genetic variation for trade-offs.

La dispersion est un processus clé dans les dynamiques de populations. Chez les organismes à dispersion passive, dont les plantes, la dispersion de la banque de graines fait appel à un vecteur biotique ou abiotique. En particulier, la zoochorie influence les patrons spatiaux de distribution et de diversité des plantes à travers une interaction entre les traits écologiques du vecteur animal et de la plante transportée. Ma thèse vise à étudier l’effet de cette interaction sur la composition taxonomique et fonctionnelle des communautés floristiques. Je me concentre sur trois questions principales : (1) Comment les traits écologiques des plantes et des vecteurs influencent-ils le processus de dispersion endozoochore? ; (2) La zoochorie constitue-t-elle un filtre d’assemblage sur les traits fonctionnels des plantes dispersées? ; (3) La zoochorie imprime-t-elle un signal sur les patrons spatiaux de diversité? J’adopte à cet effet une approche expérimentale, en me concentrant sur la flore d’Europe de l’Ouest et sur les trois ongulés sauvages les plus communs dans cette région : le cerf (Cervus elaphus), le chevreuil (Capreolus capreolus) et le sanglier (Sus scrofa). Je montre que l’interaction entre les traits des plantes et des vecteurs influe sur les durées de rétention des graines, qui influencent les distances de dispersion. L’endozoochorie modifie la composition de l’assemblage d’espèces dispersé par rapport à la flore régionale en imposant un filtre fonction de l’habitat dans lequel se nourrit le vecteur animal, mais indépendant des traits morphologiques des graines. A échelle des communautés, l’effet de la zoochorie est cependant réduit relativement aux autres processus abiotiques et biotiques tels que les filtres liés à l’habitat ou l’herbivorie. Compte tenu de ces résultats, je propose de prendre en compte l’influence de la dispersion dans les modèles prédictifs de distributions des plantes, afin d’améliorer notre compréhension des dynamiques d’aires et leur prédiction en lien avec les scénarios de changements climatiques. Il apparaît en particulier nécessaire de mieux quantifier la contribution de la dispersion zoochore aux patrons de diversité et de composition des communautés végétales, relativement aux autres processus qui résultent d’interactions plantes-animaux et aux autres modes de dispersion des graines. / Dispersal is a key process shaping population dynamics. In passive dispersers like plants, the dispersal of the seed bank relies on biotic or abiotic vectors. Among the wide range of passive dispersal, zoochory influences spatial plant diversity and distribution patterns through an interaction between the ecological traits of dispersed plants and their animal vectors. In this work, I investigate the outcomes of this interaction on the taxonomic and functional composition of plant communities. I address three main questions: (1) How do the ecological traits of dispersed plants and their vectors influence the dynamics of endozoochorous dispersal? ; (2) Does zoochory affect the functional traits of dispersed species as a community assembly filter? ; (3) What is the imprint of zoochory on spatial patterns of plant diversity? I frame my work within an experimental approach focused on the West-European flora and on the three most common wild ungulates in this area: red deer (Cervus elaphus), roe deer (Capreolus capreolus) and wild boar (Sus scrofa). I show that interactions between plant and vector traits influence dispersal distances by modulating seed retention times. Endozoochory modifies the composition of dispersed plant assemblages as compared with that of the regional pool by filtering species according to the feeding habitats of the vectors. At a community level, zoochory has a limited influence relative to other abiotic or biotic processes including habitat and herbivory. On the basis of these results, I suggest to include dispersal in predictive models of plant distributions to improve our understanding of range dynamics and their prediction especially within the framework of current global changes. My results further suggest that the contribution of zoochorie to plant diversity and community composition patterns needs to be better quantified and compared with other plant-animal interactions and other dispersal modes.

Dans un contexte de changement climatique, des dispositifs sont mis en place par les politiques publiques pour permettre le déplacement de la biodiversité et la recolonisation de nouveaux milieux (TVB, trame de vieux bois. . . ). Ces dispositifs semblent adaptés pour les espèces animales les plus mobiles. Or, les espèces ayant une faible capacité de déplacement représentent un enjeu important pour l'e‑cacité des dispositifs mis en place. Un grand nombre de ces espèces demeurent aujourd'hui mal connues. En forêt, les coléoptères saproxyliques aptères de litière sont des espèces ayant des capacités de déplacement et de dispersion limitées en raison de leurs petites tailles, de leurs aptérismes et de leurs exigences trophiques. Ces espèces constituent le modèle biologique de cette étude pour comprendre comment des espèces à faible capacité de déplacement peuvent évoluer dans les forêts et les paysages anthropisés, dans l'espace et le temps. L'échantillonnage par tamisage de litière de dix arbres par peuplement en utilisant un Winkler et une extraction par Berlese, a montré une puissance d'échantillonnage moyenne de 97.2% pour six forêts. Des relevés mensuels sur deux ans ont permis de caractériser la phénologie des espèces, à savoir qu'elles sont i/ présentes dans la litière toute l'année, ii/ davantage abondantes au printemps et en automne et iii/ ne présentent pas de variation interannuelle. Nous avons comparé la richesse spécique et la répartition des espèces, entre les forêts subnaturelles et les peuplements exploités des montagnes Pyrénéennes. Ceci a montré que les espèces sont peu impactées par l'exploitation sylvicole traditionnelle, mais présentent une grande variabilité de répartition qui semble liée à l'impact anthropique passé. Le paysage fragmenté des Coteaux de Gascogne s'est avéré être très pauvre en coléoptères saproxyliques aptères. Étonnamment, dans ce territoire, les répartitions des espèces sont mieux expliquées par les caractéristiques des paysages que celles des forêts. Pour la moitié des espèces, leurs répartitions sont mieux expliquées par la composition du paysage en 1850 que celle d'aujourd'hui. Un seuil critique de 15% de proportion de forêts dans le paysage en 1850 a pu être mis en évidence pour une espèce (Dienerella clathrata). Nous avons montré que les espèces sont capables (au moins) de se déplacer à travers les haies, quelles que soient les caractéristiques de ces dernières. Si les espèces étaient présentes dans la forêt connectée à la haie, elles ont été échantillonnées dans cette dernière. Les capacités de déplacement de trois espèces ont été étudiées en laboratoire et montrent une vitesse moyenne de 1,6m.h-1. Ces deux éléments conrment le fait que ces espèces sont mobiles dans le paysage. L'ensemble de ces résultats, ainsi que le fait que les territoires les moins anthropisés soient les plus riches en coléoptères saproxyliques aptères, nous amènent à conclure que ce groupe taxonomique supporte bien les impacts humains de faible amplitude spatiale et temporelle, mais qu'ils sont peu résilients à une anthropisation importante dans le temps et dans l'espace. / To enable species migration in a global warming context, public policies try to improve European natural network (Green and Blue infrastructure, old trees network...). These measures might be adapted to the high-dispersal species, but there is a lack of knowledge concerning the ability of the low-dispersal species to move using these networks. Lots of these species remain poorly known. Considering forest ecosystems, ightless saproxylic beetles are supposed to be dispersal limited species because of they are small, unable to y and have trophic exigencies. The aim of this study is to understand how dispersal limited species evolve temporally and spatially in the landscape. Flightless saproxylic beetles have been sampled by sieving litter in front of ten trees per stand, using a modied Winkler and extracted through an adapted Berlese. This standardization of the methods lead to sample an average of 97,2% of the species targeted in each forest. A monthly survey during two years has shown that the species are present in the litter throughout the year and that they are stable over two years. The best season to sample them appeared to be autumn and spring. Comparison between old growth forests and harvested stands in the French Pyrénnées has shown that harvesting does not impact signi cantly the target species. Their repartitions were highly dierent between the studied valleys, which is assumed to result from the dierence in the past human impact. In the highly fragmented landscape (Coteaux de Gascogne, SW France), very few ightless saproxylic species have been sampled. Surprisingly, this experiment has shown that the landscape characteristics explain better these dispersal limited species' repartitions than the forest characteristics. For half of them, landscape composition in the 1850's explain better the repartition than the current one. A threshold of 15% of forest cover appeared to be determinant for one species (Dienerella clathrata). We showed that the studied species use the edges (at least to move through them) whatever their characteristics may be. As soon as they are present in the forest, they are in the connected edge. Moving abilities of 3 species have been approached by measuring the running speed in laboratory. This experiment showed a mean of running speed of 1,6m.h -1. These dierent elements lead us to conclude that the ightless saproxylic beetles are mobile in the landscape. All these results, and the fact that species richness is correlated to the landscape anthropisation, leads us to conclude that this taxonomic group can support human impact at small spatial and temporal scale, but are poorly resilient to large and long anthropisation.